Phong it up on the ground plane.

4 files changed, 15 insertions, 121 deletions

diff --git a/glass.c b/glass.c
index 9eae85f..ab214a8 100644
--- a/glass.c
+++ b/glass.c
@@ -78,6 +78,7 @@ struct uniform_desc uniforms[] = {
 struct uniform_desc ground_uniforms[GROUND_UNIFORM_MAX] = {
 	[GROUND_UNIFORM_MV] = { "mv" },
 	[GROUND_UNIFORM_MVP] = { "mvp" },
+	[GROUND_UNIFORM_LIGHT_EYE] = { "light_eye" },
 };
 
 
diff --git a/glass.h b/glass.h
index 39d0355..524fb40 100644
--- a/glass.h
+++ b/glass.h
@@ -32,6 +32,7 @@
 enum ground_uniform_list {
 	GROUND_UNIFORM_MV,
 	GROUND_UNIFORM_MVP,
+	GROUND_UNIFORM_LIGHT_EYE,
 	GROUND_UNIFORM_MAX
 };
 
diff --git a/ground.frag b/ground.frag
index 1938364..a9cd20c 100644
--- a/ground.frag
+++ b/ground.frag
@@ -1,125 +1,16 @@
-void main()
-{
-	gl_FragColor = vec4(1,0,0,0);
-}
-
-#if 0
-varying vec3 light_surf;
-varying vec3 eye_surf;
-varying vec3 tangent_surf;
-varying vec2 texcoord;
-uniform sampler2D normal_sampler;
-uniform sampler2D heightmap_sampler;
-uniform float F0, ni;
-
-float schlick_fresnel(float n_dot_l)
-{
-	return F0 + (1 - F0) * pow(1 - n_dot_l, 5);
-}
-
-/* This returns garbage compared to Schlick. */
-float fresnel(float v_dot_h)
-{
-	float c = v_dot_h; /* cos theta, v . h or l . h */
-	float g = sqrt(ni * ni + c * c - 1);
-	float gmc = g - c;
-	float gpc = g + c;
-	float c_gpc_m_1_squared = (c * gpc - 1) * (c * gpc - 1);
-	float c_gmc_p_1_squared = (c * gmc + 1) * (c * gmc + 1);
-
-	return gmc*gmc / (2 * gpc*gpc) * (1 + c_gmc_p_1_squared /
-					  c_gpc_m_1_squared);
-}
+uniform vec3 light_eye;
+varying vec3 vertex_eye;
 
 void main()
 {
-	const vec4 material_color = vec4(0.7, 0.5, 0.3, 0.0);
-	vec3 l = normalize(light_surf);
-	vec3 v = normalize(eye_surf);
+	vec3 normal = vec3(0.0, 0.0, 1.0);
+	const vec4 material_color = vec4(1.0, 0.7, 0.3, 0.0);
+	vec3 l = normalize(light_eye - vertex_eye);
+	vec3 v = normalize(-vertex_eye);
 	vec3 h = normalize(l + v);
-	vec3 t = normalize(tangent_surf);
-	vec3 n = texture2D(normal_sampler, texcoord).xyz * 2 - 1;
-	/* Hack: Reduce the significance of our normal map, which otherwise
-	 * looks incongruous with the straight edges.
-	 */
-	n = normalize(n + vec3(0,0,1));
-	float n_dot_l = dot(n, l);
-	float n_dot_v = dot(n, v);
-	float n_dot_h = dot(n, h);
-	float v_dot_h = dot(v, h);
-	float s = .7;
-	float d = 1 - s;
-	float Ii = 0.9; /*intensity of incoming light */
-	float Iia = .1 * Ii; /*intensity of ambient light */
-
-	float cos2_alpha = n_dot_h * n_dot_h;
-	float tan2_alpha = (1 - cos2_alpha) / cos2_alpha;
-	float Rs;
-	float D;
-
-	/* Aniso BRDF from Ward's "Measuring and Modeling
-	 * Anisotropic Reflection".
-	 */
-
-	/* brushed metal */
-	float ward_n = .037;
-	float ward_m = .063;
-
-	/* Make phi be the angle between the projections of
-	 * the tangent and half-angle vectors onto the
-	 * surface plane (z=0).  Doing it right would involve
-	 * projecting onto the plane defined by n.
-	 */
-	float cos_phi = dot(normalize(t.xy), normalize(h.xy));
-
-	float cos2_phi_over_m2 = ((cos_phi * cos_phi) / (ward_m * ward_m));
-	float sin2_phi_over_n2 = ((1 - cos_phi * cos_phi) / (ward_n * ward_n));
-#if 1
-	D = exp(-tan2_alpha * (cos2_phi_over_m2 + sin2_phi_over_n2));
-#else
-	/* Ward's "computationally convenient" equation.
-	 * Doesn't work.
-	 */
-	D = exp(-2 * (cos2_phi_over_m2 +
-		      sin2_phi_over_n2) /
-		(1 + n_dot_h));
-#endif
-	Rs = 2 * schlick_fresnel(n_dot_l) * D /
-	  sqrt(n_dot_l * n_dot_v) / (ward_m * ward_n);
-
-	Rs *= step(0, n_dot_l);
-	Rs *= step(0, n_dot_v);
-
-	float Rd = (1 - F0) * 2;
-	/* Ambient occlusion factor -- sample the height map we
-	 * used to generate the normal map, and reduce intensity in
-	 * the valleys.
-	 */
-	float heightmap = texture2D(heightmap_sampler, texcoord).x;
-	float Ra = Rd * (.8 + .2 * heightmap);
-
-	gl_FragColor = n_dot_l * step(0, n_dot_l) *
-	  vec4(material_color.xyz *
-	       (Rd * d + Rs * s),
-	       material_color.w) +
-	  Iia * Ra * material_color.xyzw;
-
-	/* Debugging scalars -- Map [0,1] to [0.5,1] to catch negative
-	 * values.  Multiply by the step function to catch when
-	 * the scalar won't come into play because Rs == 0.
-	 */
-#if 0
-	gl_FragColor = vec4(vec3(F0 / 2 + .5), 1);
-#endif
-/* Normal visualization */
-/*
-vec3 temp = vec3((normal.x + 1) / 2,
-		  (normal.y + 1) / 2,
-		  (normal.z + 1) / 2);
-gl_FragColor = vec4(temp.xyz, 0);
-*/
-/*
-	gl_FragColor = texture2D(normal_sampler, texcoord);
-*/
+	float n_dot_l = dot(normal, l);
+	vec3 diffuse = material_color.xyz * n_dot_l;
+	float specular = pow(dot(normal, h), 16.0);
+	gl_FragColor = step(0.0, n_dot_l) *
+	vec4(diffuse + vec3(specular), material_color.w);
 }
-#endif
\ No newline at end of file
diff --git a/ground.vert b/ground.vert
index a1e3dd9..549636b 100644
--- a/ground.vert
+++ b/ground.vert
@@ -4,6 +4,7 @@ varying vec3 light_surf;
 varying vec3 eye_surf;
 varying vec3 tangent_surf;
 */
+varying vec3 vertex_eye;
 uniform mat4 mvp, mv;
 
 void main()
@@ -12,13 +13,13 @@ void main()
 	vec3 n = (mv * vec4(gl_Normal, 0.0)).xyz;
 */
 	gl_Position = mvp * gl_Vertex;
+	vertex_eye = vec3(mv * gl_Vertex);
 /*
 	mat3 tbn = mat3(t,
 			cross(n, t),
 			n
 			);
 
-	vec3 vertex_eye = vec3(mv * gl_Vertex);
 
 	texcoord = vec2(gl_MultiTexCoord0.x * 4, gl_MultiTexCoord0.y);
 	light_surf = normalize((light_eye - vertex_eye) * tbn);